Well, unfortunately they did extremely heavy global nr on the shots again (compare the details on iso 50 to the other studio shots), obviously to them a noise-free black background is more important than details :-x ... hail to raw and the LR nr brush!

But looking at the iso samples it might be clean 6400 and the the 51200 iso shot look better than 6400 on my 60d, so if it's a 3 stop improvement over the current crop sensor I'd say that's a definitive step up :-) ... on the other hand side we don't know how the dynamic range degrades @high iso.

I didn't see lens profile on your 5D III pictures, I'm assuming that you used same lens. Since you shot these pictures in studio, the light becomes MAJOR role. I do not believe your light setups were the same, in term of location and height.

Picture below was shot at f11 with 250W studio light in low light location, not the best , but it does show what 5D III can produce.

I agree it does look like the 6D is a little bit better at noise. The better colour could just be from changes in lighting between dpreviews setups, it's hard to tell. However the default NR on the latest Canon cameras has been far too heavy handed of late, and it shows in the other samples as well. Need to see some RAW files before we can really tell (but that will need to wait for RAW support). Although seeing the 6D jpeg better than the 5DIII jpeg, does suggest the larger pixel pitch is doing what would be expected (assuming no major changes to the jpeg engine of course).

I didn't see lens profile on your 5D III pictures, I'm assuming that you used same lens. Since you shot these pictures in studio, the light becomes MAJOR role. I do not believe your light setups were the same, in term of location and height.

Those pictures are from DPReview, we can only assume they used the same lighting setups, but it's possible they didn't manage to keep it exactly the same.

Picture below was shot at f11 with 250W studio light, not the best but it does show how sharp the 5D III can produce.

At iso 100 like your shot you hardly need a 5d3 to produce a good result (actually the 5d2 is said to be a bit sharper at low iso due to the weaker aa filter). Esp. for studio shots putting money into a sharp lens might be smarter than the newest camera body...

The jpeg iso samples of dpreview are to compare noise, in the way that you can see what's left of the details after nr. I guess dpreview is a reliable site and they had the same setup, and imho the 6d is indeed visibly better in these shots (detail left and noise in background) - I just loaded all into lightroom and compared them side by side.

So either Canon at last really did something about their sonsors (rejoice!) or the 5d3 shots were done with an older firmware version that had a worse in-camera jpeg converter - we have to wait for a 6d software raw converter and raw shots to be sure.

6D looks better so far but is logical from my view. To have a body that is cleaner image wise but slower in AF and FPS. This makes me excited as a 450D user looking at the near endless possibilities. Just curious what the 7ad2 will do.